Causes of thermocouple temperature difference

 A thermocouple is actually a kind of energy converter, which converts heat energy into electrical energy, and uses the generated thermoelectric potential to measure the temperature. The following are the reasons for the temperature error of the muffle furnace thermocouple compiled for everyone:

　　1) The influence of thermocouple instability. Instability refers to the change of thermocouple's graduation value with time and use conditions. Normally, thermocouple is the main factor of temperature instability. The volatilization, oxidation, crystallization and other factors of the thermoelectrode at high temperature are the reasons for the instability of the thermocouple.

　　 2) The influence of the non-uniformity of the thermocouple. If the thermocouple is made of a homogeneous conductor, then the thermoelectric potential is only related to the temperature at both ends; if the thermoelectrode material is not uniform and there is a temperature gradient field, the thermocouple will generate an additional heat trend, and the size of the temperature error It also depends on the state of the temperature gradient distribution, the uneven form of the material and the degree of unevenness.